You might be interested in this new AM adjustment device from
Tyler KW0AM (neat call): http://www.cleanrf.com/
de ken n9vv
Bob McGraw - K4TAX wrote:
> To correctly set these radios for AM one should have some type of waveform
> monitor such as the old Heath SB-610 or HO-10.
>
> One thing that I noticed with my Omni VII and the 708A mike. The Positive
> modulation peaks were not 100% when the negative peaks were hitting 100%.
> The solution, reverse the Red and White wires in the XLR-4 connector that
> plugs into the back of the mike. Once this was done, the positive
> modulation is equal to the negative modulation. Without a waveform monitor
> being a Heath SB-610, I'd never seen the issue. And yes, it takes more mike
> gain for AM than for SSB.
>
> Even with the Heath Apache and the RCA BC transmitter I have found that mike
> phase does make a difference in modulation symmetry. A monitor scope will
> tell the true story.
>
>
> 73
> Bob, K4TAX
>
>
> ----- Original Message -----
> From: <ac9s@mchsi.com>
> To: <tentec@contesting.com>
> Sent: Tuesday, October 02, 2007 2:52 PM
> Subject: [TenTec] Orion II AM Mic Adjustment
>
>
>> I have begun to play with AM on the O2 and it appears the microphone
>> settings
>> are significantly different than with SSB. I am running a Heil Goldline
>> through an NCS multiswitcher. With the current gain setting on the NCS
>> box I
>> have the red led on the O2 flickering with the O2 software mic setting at
>> 18.
>> Today I checked in with an AM group on 3875khz and was informed that my
>> audio
>> was light. Sure enough, there was no flicker on the led. I turned the
>> mic
>> gain almost up to 100 - I could see increased gid current on my amplifier,
>> but
>> never a sign of the led lighting. The group informed me the audio level
>> had
>> increased, but that it was still a little on the light side.
>>
>> Does the LED work on AM? Should the mic gain be radically different
>> between
>> SSB and AM? I didn't see anything specific in the manual.
>>
>> Thanks for any input on the proper way to set the mic gain on AM.
>>
>> Keith
>> AC9S
>> _______________________________________________
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>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
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